[3.5e] Final Battle Magic Items-

[Goldlizard]

My group is assembling an army (we are level 12) to attack another army of Tiamat Spawn, we have around 100K gold each to spend on magic items to prepare for the battle, what should my character purchase?

Relevant items/feats/ect.
My character is a Human Binder/Knight of the Sacred Seal 5.
Their primary weapon is a +1 Mythral Longspear.
Their armor is a +1 Fearsome Mythral Breastplate
Their Patron Vestige is amon, but they almost certainly will have Zyrcell bound as a second vestige.

They have very high ranks in Intimidate and have Never Outnumbered with Imperious Command
They have a cloak of Charisma, the lowest available grade.
They are LG and have the Outsider type.

The DM allows any official 3.5e Source that is not the Dragon Magazine. Anything else is up to approval.

I can answer any other information you need answered. What do you recommend I get?

[MaxiDuRaritry]

Add sizing to your weaponry and purchase a psychoactive skin of proteus (https://www.d20srd.org/srd/psionic/items/universalItems.htm#skinofProteus) for 84k. ML 7 metamorphosis at will is crazy-good, not the least of which is because it allows healing at will. Add +1 ML via Words of Creation (for free) if you can swing it.

The sizing is so you can use your weapons no matter what size your new forms take.

[Goldlizard]

Add sizing to your weaponry and purchase a psychoactive skin of proteus (https://www.d20srd.org/srd/psionic/items/universalItems.htm#skinofProteus) for 84k. ML 7 metamorphosis at will is crazy-good, not the least of which is because it allows healing at will. Add +1 ML via Words of Creation (for free) if you can swing it.

The sizing is so you can use your weapons no matter what size your new forms take.

Should also mention my type is Outsider via KoSS 5

[MaxiDuRaritry]

Should also mention my type is Outsider via KoSS 5That's fine. Metamorphosis works on you regardless of type, although non-outsiders can't turn into outsiders using it (but since you are one, you can use it to turn into other outsiders).

"You assume the form of a creature of the same type as your normal form, or any other type except construct, elemental, outsider, and undead."